System and methods for harvesting and processing periosteum fibers

ABSTRACT

Periosteum harvesting and processing systems and methods enable rapid, efficient, and repeatable harvesting of periosteum tissue from human long bones and processing of the tissue into individual fibers for use in strengthening surgical allograft products. One harvesting and processing method involves providing a human long bone, securing the long bone between two rotating live centers, scraping, using one of a plurality of harvesting tools selected from a harvesting and processing kit, periosteum tissue from the long bone, executing a first wash cycle comprising a hydrogen peroxide wash, executing a second wash cycle comprising an isopropyl alcohol wash, executing a third wash cycle comprising a phosphate buffered saline wash, compressing the periosteum tissue to remove excess fluid, cryofracturing the tissue until a desired fiber size is achieved, and separating the periosteum tissue into individual periosteum fibers having the desired fiber size. Other embodiments are also disclosed.

REFERENCE TO PRIOR PATENT APPLICATION

This application claims the benefit under 35 U.S.C. 119 (e) of U.S. Provisional Patent Application No. 62/732,210, filed Sep. 17, 2018 by Megan Maccagnan, Cameron Mattson, Cole Watkins, Adrian C. Samaniego, and William Maslanik for “SYSTEM AND METHODS FOR HARVESTING AND PROCESSING PERIOSTEUM FIBERS,” all of which patent application is hereby incorporated herein by reference.

BACKGROUND

An allograft includes bone, tendon, skin, or other types of tissue that is transplanted from one person to another. Allografts are used in a variety of medical treatments, such as knee replacements, bone grafts, spinal fusions, eye surgery, and skin grafts for the severely burned. Allografts come from voluntarily donated human tissue obtained from cadaveric donor-derived, living-related, or living-unrelated donors and can help patients regain mobility, restore function, enjoy a better quality of life, and even save lives in the case of cardiovascular tissue or skin.

FIG. 1 illustrates a cross-sectional, partial view of a human long bone 10 having a diaphysis (shaft) 12 extending between epiphyses (ends) 14. A periosteum 16 provides a dense layer or membrane of vascular connective tissue that envelops the bone except at the surfaces of the joints. The periosteum 16 borders the dense outer surface of the bone, known as cortical bone 18. Fibers of periosteum are oftentimes used to increase material cohesiveness and provide structural integrity to allograft products designed to be surgical grafts, in a manner similar to the use of rebar within concrete structures. For example, periosteum fibers are often incorporated into surgical grafts for promoting graft cohesiveness in spinal fusion procedures.

Currently, no efficient mechanisms or methods exist for the rapid harvesting of periosteum from human long bones or for processing the periosteum into individual fibers that may then be implemented within surgical allografts. Existing tools and methods present time, efficiency, efficacy, and repeatability challenges.

SUMMARY

This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key aspects or essential aspects of the claimed subject matter. Moreover, this Summary is not intended for use as an aid in determining the scope of the claimed subject matter.

One embodiment provides a composition of periosteum fibers for use in strengthening a surgical allograft prepared by a method comprising the following steps: (1) providing a human long bone including a diaphysis extending between two epiphyses and having an outer layer of a periosteum tissue; (2) removing the epiphyses and securing the diaphysis between two rotating live centers; (3) removing, using one of a plurality of harvesting tools selected from a harvesting and processing kit, the periosteum tissue from the diaphysis; (4) executing a first wash cycle comprising washing the periosteum tissue in a hydrogen peroxide solution; (5) executing a second wash cycle comprising washing the periosteum tissue in an isopropyl alcohol solution; (6) executing a third wash cycle comprising washing the periosteum tissue in a phosphate buffered saline (PBS); (7) compressing the periosteum tissue; (8) cryofracturing the periosteum tissue into a quantity of fused periosteum fibers; and (9) separating the quantity of the fused periosteum fibers into a plurality of individual periosteum fibers.

Another embodiment provides a method of harvesting and processing bulk periosteum tissue. The method may include the following steps: (1) removing, using one or more harvesting tools, a quantity of bulk periosteum tissue from an outer surface of a human long bone; (2) first washing the quantity of the bulk periosteum tissue in a volume of hydrogen peroxide; (3) second washing the quantity of the bulk periosteum tissue in a volume of isopropyl alcohol; (4) third washing the quantity of the bulk periosteum tissue in a volume of phosphate buffered saline (PBS); (5) compressing the quantity of the bulk periosteum tissue; (6) cryofracturing the quantity of the bulk periosteum tissue until the quantity of the bulk periosteum tissue comprises a plurality of individual periosteum fibers; and (7) using a fiber separator tool to separate the plurality of the individual periosteum fibers from one another.

Yet another embodiment provides a method for harvesting and processing periosteum tissue, including the following: (1) providing a periosteum harvesting and processing kit comprising a plurality of periosteum harvesting tools configured for removing an outer layer of periosteum tissue from a human long bone, at least one sieve, at least one compression tool, and a periosteum fiber separator; (2) using at least one of the plurality of the periosteum harvesting tools, removing the periosteum tissue from the human long bone; (3) thrice repeating a first hydrogen peroxide wash cycle; (4) first drying the periosteum tissue; (5) twice repeating a second isopropyl alcohol wash cycle; (6) second drying the periosteum tissue; (7) performing a third phosphate buffered saline (PBS) wash cycle; (8) third drying the periosteum tissue; (9) compressing the periosteum tissue using the at least one compression tool; (10) cryofracturing the periosteum tissue into a plurality of fused periosteum fibers; and (11) separating the plurality of the fused periosteum fibers into a plurality of individual periosteum fibers using the periosteum fiber separator.

Other embodiments are also disclosed.

Additional objects, advantages and novel features of the technology will be set forth in part in the description which follows, and in part will become more apparent to those skilled in the art upon examination of the following, or may be learned from practice of the technology.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive embodiments of the present invention, including the preferred embodiment, are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified. Illustrative embodiments of the invention are illustrated in the drawings, in which:

FIG. 1 illustrates a partial cross-sectional view of a human long bone, including a layer of periosteum tissue bordering the cortical bone;

FIGS. 2A-2B provide a flowchart depicting an exemplary method for harvesting periosteum tissue and processing it into individual periosteum fibers;

FIG. 3 illustrates a side view of a long bone diaphysis mounted between two live centers;

FIG. 4 provides a functional block diagram depicting one embodiment of a periosteum harvesting and processing kit;

FIGS. 5-9 illustrate respective left-perspective, top, right-perspective, rear-perspective, and front views of one embodiment of a periosteum fiber separator tool; and

FIG. 10 illustrates a side-plan view of another embodiment of a periosteum fiber separator tool.

DETAILED DESCRIPTION

Embodiments are described more fully below in sufficient detail to enable those skilled in the art to practice the system and method. However, embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. The following detailed description is, therefore, not to be taken in a limiting sense.

Various embodiments of the systems and methods described herein relate to efficiently and rapidly harvesting the periosteum 16 from human long bones 10 (FIG. 1 ) and processing the harvested bulk periosteum tissue 16 into periosteum fibers for subsequent use in supporting and adding structural integrity to other surgical allograft products. In one embodiment, a periosteum harvesting and processing method may involve scraping or otherwise stripping the periosteum tissue 16 from the long bone, followed by a series of periosteum washing, isolation, compression, cryofracturing, and fiber separation steps. A number of tools may be implemented to carry out the periosteum harvesting and processing method. The tools may be incorporated within a periosteum harvesting and processing kit having a selection of instruments such as scalpels, cheese wires, radius card scrapers, and small radius gouges, each configured for scraping the periosteum 16 from the long bone 10. The kit may also include absorbent materials for fluid removal, compression tools, and separation tools specifically configured for separating clumps of processed bulk periosteum tissue into individual periosteum fibers.

Turning to the exemplary embodiments shown in the figures, FIGS. 2A-2B provide a flowchart depicting an exemplary method (100) of harvesting periosteum from a human long bone 10 and processing it into individual periosteum fibers. In this embodiment, the method (100) initiates with removing the epiphyses 14 of the long bone 10 and securing the diaphysis 12 of the human long bone 10 between two live centers 20 (e.g., lathe centers) for continuous rotation of the long bone (102), as shown in the schematic of FIG. 3 . The method (100) may continue with scraping or removing the periosteum tissue 16 from the rotating long bone 10 until only the cortical bone 18 remains (104), utilizing one or more periosteum harvesting or scraping tools selected from an embodiment of a periosteum harvesting and processing kit 30, as shown in in FIG. 4 .

In this regard, FIG. 4 provides a functional block diagram depicting one embodiment of the harvesting and processing kit 30 featuring a plurality of periosteum harvesting or scraping tools 32 _(1-n) including, for example, one or more scalpels 32 ₁, cheese wires 32 ₂, radius card scrapers 32 ₃, and/or small radius gouges 32 ₄. Embodiments of the harvesting and processing kit 30 may also include any appropriate number, variety, and/or type of additional tools necessary to efficiently and rapidly divest the bone 10 of the periosteum tissue 16, as well as tools for further processing of the periosteum 16 including, for instance, one or more forceps 34, sterile absorbent wipes 36, sieves 40, and/or compression tools 38 such as rollers, as discussed in use below.

Returning to FIGS. 2A-2B, and once the periosteum tissue 16 has been scraped from the bone 10, the periosteum tissue 16 undergoes a first wash cycle (106) involving three repetitions of a first wash (108), each time with a 200 ml volume of 6% hydrogen peroxide for five minutes with agitation. After each first wash (108), the periosteum tissue 16 may be isolated using a 125-micron sieve to remove excess hydrogen peroxide (110). After the third repetition of the first hydrogen peroxide wash (108) and the third isolation (110), the periosteum tissue 16 may be dried using pressure applied through one or more of the sterile absorbent wipes 36 (112).

Next, the periosteum tissue 16 may undergo a second wash cycle (114) involving two repetitions of a second wash (116), each time with a 200 ml volume of 70% Isopropyl alcohol for 5 minutes with agitation. After each second wash (116), the periosteum 116 may be isolated or recovered with the 125-micron sieve (118). Following the second repetition of the second wash (116) and the second sieve isolation (118), the periosteum tissue 16 may again be dried using pressure applied through one or more of the sterile absorbent wipes 36 (120).

After the second wash cycle (114), the periosteum tissue 16 undergoes a third wash cycle (122) involving a single third wash (124) with a 200 ml volume of phosphate buffered saline (PBS) for 5 minutes. After this third wash (124), the periosteum tissue 16 is isolated (126) using the 125-micron sieve 40 to remove the excess PBS. The periosteum tissue 16 is then dried using pressure (e.g., manual pressure) applied through one or more of the sterile absorbent wipes 36 (128).

After completing the first, second, and third wash cycles (106, 114, 122), the periosteum tissue 16 may be laid upon a clean sterile absorbent wipe 36 in a manner that results in the tissue having a consistent thickness (130). In one embodiment, the wipe 36 may folded or wrapped around the periosteum tissue 16 (132) before the wipe 36, containing the periosteum tissue 16 therein, is rolled through a space between two adjacent rollers 38 or other compression tools (134), thereby compressing the periosteum/wipe configuration and removing any excess fluids from the periosteum tissue 16. In one embodiment, the periosteum/wipe configuration is rolled at least five times through the rollers 38. After each pass, the rollers may be moved incrementally closer together to incrementally decrease the space between the rollers and provide a resulting incremental increase in periosteum tissue compression (136).

Once the periosteum tissue 16 has been rolled/compressed (134, 136), it may be removed from the sterile absorbent wipe 36 (138) using the sterile forceps 34 before being freeze fractured, or cryofractured (140), utilizing, in one embodiment, the cryofracturing method or a modification of the cryofracturing method disclosed in issued U.S. Pat. No. 9,801,976B2. With a limited volume of crushed dry ice added to a cryofracturing chamber, two-second pulses of cryofracturing may be applied until a desired fiber size of the periosteum tissue 16 is achieved. The crushed dry ice and periosteum fiber mixture are then removed from the cryofracturing chamber and laid on a clean sterile wipe 36 to allow for the dry ice to evaporate (142).

After complete evaporation of the dry ice (142), the clumps of bulk periosteum tissue 16, each formed of a plurality of fused periosteum fibers, may be separated into individual periosteum fibers (144) by processing the bulk tissue through a separation tool or separator that may be included in the periosteum harvesting and processing kit 30 of FIG. 4 .

FIGS. 5-9 illustrate left-perspective, top, right-perspective, rear-perspective, and front views of one embodiment of a fiber separator 42, respectively. In this embodiment, the fiber separator 42 may include a housing 44 containing first and second sets of overlapping, circular serrated blades 46 a, 46 b configured for counterrotation during operation. The first blade set 46 a may be operatively coupled with a first gear 48 a via a first drive shaft 51 a, and the second blade set may be operatively coupled with a second gear 48 b via a second drive shaft 51 b. The gears 48 a, 48 b may be enmeshed such that, when at least one of the gears 48 a, 48 b is rotated, the blades of the respective attached blade sets 46 a, 46 b rotate in opposite directions. The gears 48 a, 48 b may take any appropriate size, shape, and/or configuration. As shown, the gear 48 a, 48 b may include or be attached to manual knobs 52 a, 52 b to facilitate the rotation of the gears. In other embodiments, the gears 48 a, 48 b may be attached to other types of knobs or cranks as desired and/or appropriate. In some embodiments, the gears may be operatively coupled with one or more motors or actuators and controlled electronically.

As the bulk periosteum tissue 16 is passed into contact with an overlapping portion 53 of the first and the second blade sets 46 a, 46 b, the blades 46 a, 46 b impinge upon the clumps of periosteum tissue 16 such that a number of blade teeth 50 separate the tissue 16 into its individual fibers 21 as the blades 46 a, 46 b travel from a first end 17 to a second end 19 of the bulk periosteum tissue 16, as shown in FIGS. 8-9 . In one embodiment, the bulk tissue 16 may be passed from a top side of the housing 44 and through the counterrotating blade sets 46 a, 46 b, such that the separated fibers 21 pass out of the housing 44 through an exit aperture 54 formed in a bottom of the housing 44 for collection and use.

In another embodiment shown in FIG. 10 , an alternative fiber separator 60 may include first and second opposing blocks 62, each having exposed pin heads 64. The bulk tissue 16 may be placed on the first block 62 and the second block 62 may be placed thereupon along a direction designated by arrow A, such that the pins 64 are used to separate the fibers of the periosteum 16 using a combing motion directed along a longitudinal direction designated by arrow B and/or a lateral direction designated by arrow C, as required for the appropriate surgical application.

Using the systems and associated tools and methods of use described above, a technician or other allograft preparation professional may harvest periosteum tissue 16 from a human long bone 10 and process the tissue into individual periosteum fibers for later use in strengthening surgical allograft products in a manner that is quick, efficient, reliable, and repeatable.

Although the above embodiments have been described in language that is specific to certain structures, elements, compositions, and methodological steps, it is to be understood that the technology defined in the appended claims is not necessarily limited to the specific structures, elements, compositions and/or steps described. Rather, the specific aspects and steps are described as forms of implementing the claimed technology. Since many embodiments of the technology can be practiced without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended. 

1. A composition of periosteum fibers for use in strengthening a surgical allograft prepared by a method comprising: providing a human long bone including a diaphysis having an outer layer of a periosteum tissue; securing the diaphysis between two rotating live centers; removing, using one of a plurality of harvesting tools selected from a harvesting and processing kit, the periosteum tissue from the diaphysis; executing a first wash cycle comprising washing the periosteum tissue in a hydrogen peroxide solution; executing a second wash cycle comprising washing the periosteum tissue in an isopropyl alcohol solution; executing a third wash cycle comprising washing the periosteum tissue in a phosphate buffered saline (PBS); compressing the periosteum tissue; cryofracturing the periosteum tissue into a quantity of fused periosteum fibers; and separating the quantity of the fused periosteum fibers into a plurality of individual periosteum fibers.
 2. The composition of periosteum fibers for use in strengthening a surgical allograft prepared by the method of claim 1, wherein the executing the first wash cycle comprises: executing three hydrogen peroxide washes of the periosteum tissue, each of the three hydrogen peroxide washes comprising a 200 ml volume of a 6% hydrogen peroxide solution for five minutes; after the executing of each of the three hydrogen peroxide washes, isolating the periosteum tissue using a 125-micron sieve; and drying the periosteum tissue.
 3. The composition of periosteum fibers for use in strengthening a surgical allograft prepared by the method of claim 2, wherein the executing the second wash cycle comprises: executing two isopropyl alcohol washes of the periosteum tissue, each of the two isopropyl alcohol washes comprising a 200 ml volume of a 70% isopropyl alcohol solution for five minutes; after the executing of each of the two isopropyl alcohol washes, isolating the periosteum tissue using the 125-micron sieve; and drying the periosteum tissue.
 4. The composition of periosteum fibers for use in strengthening a surgical allograft prepared by the method of claim 3, wherein the executing the third wash cycle comprises: executing a PBS wash comprising a 200 ml volume of the PBS for five minutes; isolating the periosteum tissue using the 125-micron sieve; and drying the periosteum tissue.
 5. The composition of periosteum fibers for use in strengthening a surgical allograft prepared by the method of claim 1, wherein the compressing the periosteum tissue comprises passing the periosteum tissue through a space between two adjacent rollers.
 6. The composition of periosteum fibers for use in strengthening a surgical allograft prepared by the method of claim 1, wherein the separating the quantity of the fused periosteum fibers comprises using a separator to impinge upon the quantity of the fused periosteum fibers such that the fused periosteum fibers fracture apart into the plurality of the individual periosteum fibers.
 7. The composition of periosteum fibers for use in strengthening a surgical allograft prepared by the method of claim 6, wherein the separator comprises: first and second opposing blocks, each of the first and the second opposing blocks having an opposing inner surface with a plurality of pins protruding proximally-to-distally therefrom, wherein when the quantity of the fused periosteum fibers is positioned between the opposing inner surfaces of the first and the second opposing blocks, the plurality of the pins impinge upon the quantity of the fused periosteum fibers and separate the fused periosteum fibers into the plurality of the individual periosteum fibers.
 8. The composition of periosteum fibers for use in strengthening a surgical allograft prepared by the method of claim 6, wherein the separator comprises: first and second overlapping and counterrotating blade sets; a first gear operatively coupled with the first blade set; a second gear operatively coupled with the second blade set, wherein: the first and the second gears are enmeshed such that rotating one of the first and the second gears rotates the first and the second blade sets in opposite directions; and when the quantity of the fused periosteum fibers contacts an overlapping portion between the first and the second blade sets, the first and the second blade sets impinge upon the quantity of the fused periosteum fibers such that the fused periosteum fibers separate into the plurality of the individual periosteum fibers as the first and the second blade sets travel from a first end to a second end of the quantity of the fused periosteum fibers.
 9. The composition of periosteum fibers for use in strengthening a surgical allograft prepared by the method of claim 1, wherein the plurality of the harvesting tools of the harvesting and processing kit comprise at least a scalpel, a cheese wire, one or more radius card scrapers, and one or more small radius gouges.
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